Defense attorneys trying to spare David Westerfield's life put his friends and colleagues on the stand Thursday to testify that the killer of 7-year-old Danielle van Dam is a caring person whose work has helped thousands.

"He's a very creative guy ... a very talented guy," said Carmen Genovese, a San Diego businessman who winked at Westerfield as he took the stand in the second day of the penalty phase of his trial.

Westerfield, 50, was convicted Aug. 21 of kidnapping Danielle from her second-floor bedroom and killing her. Her body was found

The same jury that found him guilty will be asked to recommend whether Westerfield should be sentenced to life in prison or be put to death.

Defense attorney Steven Feldman planned to call friends of Westerfield's to testify about his client's "wonderful, caring" side. Genovese and Ron Lawrence, both longtime business associates of Westerfield's, talked about the importance of his work as an engineer.

Westerfield helped design a remote underwater camera that has spared deep-sea divers from potentially risky work, Lawrence said. Medical devices Westerfield also helped design aided thousands of people recovering from surgery, Genovese said.

On cross-examination, prosecutor Jeff Dusek sought to portray Westerfield's role in the development of the devices as limited and motivated by profit.

"Basically, this was his job," Dusek said.

Westerfield's attorneys sought to undo the emotional testimony presented earlier by the prosecution.

Jurors on Wednesday heard Danielle's parents tearfully recall her short life and the painful toll of her death on them and on Danielle's brothers.

"She was one of the most precious gifts anyone could ever receive," said Danielle's mother, Brenda van Dam.